I doubt there is, but from my own experience, thoughts (and advice from others) there are some things that I just would or wouldn't do. As said before, I'm no expert, but here's my thoughts:
What should you wear to a grad school program visit?
Okay, this can depend on what type of visit it is -- is it just an open house, are you doing a one-on-one visit, are you meeting faculty?-- and how laid-back the department is. Although, even if the department is laid-back, that doesn't mean you should be... after all first impressions count! At my latest visit, which was an open house, I saw prospective students wearing shorts and tanks tops. To me, that wouldn't make a great first impression. That attire is okay for visiting undergraduate programs, but graduate programs are meant to prepare you for a career, so I wouldn't do that. If anything, I'd suggest at least nice jeans and a blouse + cardigan... if you want to dress more nicely, then opt for a dress or slacks and a blouse. You don't need to go all out and wear dress pants and a blazer/jacket, but you don't want to look like you strolled in from the beach either. (Several others on SLP student forums agree with me on this as well.)
What should I bring to the visit?
Come with at least some background knowledge of the program. Know if you'll need pre-reqs if you're an out-of-major applicant. Figure out the length of the program beforehand. Find out if they have an on-site clinic. Most of your questions can be answered by a simple visit to their webpage, and if you're truly interested in going you want to show you've done the basic homework. There were quite a few at my visit that didn't know the basics of the program (and didn't look at the FAQ sheet provided), and thus asked about these when the information was in their hands and a few clicks away.
Notepad and Pen. These can be helpful when you find something interesting about the program and don't want to forget it... like a state-of-the-art lab or new technology that they are implementing. This is also helpful for writing down any questions that you have during the presentation, as well as contact information of the faculty or admissions correspondent.
When should I arrive?
Treat it as a job interview. If you know it's in a high traffic area, try to leave you house earlier. I'd suggest 15 minutes prior to the event, that way you have time to sign-in, go to the bathroom, find the room and get a seat. It's understandable that you might get caught up in some traffic, but it's always better to be there very early than late, so try to plan accordingly.
Should I come with questions?
This is entirely up to you. If you have scoured the website and know what faculty you are interested in but find that you don't have questions, then don't worry. Or, if you're just going to check out the area, the program/clinic and dynamics and feel as if you have no questions, that's fine. Just make sure you introduce yourself and perhaps mention some faculty, class or research you are interested in. You can even try to see if a student is there that is willing to give you their contact information.
If you do want to ask questions, make sure they aren't already answered on the website. Personalize them if you want-- for example, I'm interested in the medical track so I asked how we are placed in the clinics and if they offer any additional certifications in MBSS or LVST.
Hopefully some of these help! If you can think of any other visit do's or don'ts (or perhaps think the opposite about one of mine) feel free to comment below!