I'm not aware of anyway to embed a visio file in a topic in RH - certainly "the internet" doesn't understand visio and won't display the file (although you can certainly include them as a file for download).
What I do is once I've created my visio file and saved it to a central location for later updates, I select File > Save As and save it as png (or jpg or gif or whatever) in my project with the same name as my visio file (so I can identify where the png came from). Then when it's time to update, I update my visio, then Save As over the same image in my project.
If you're using image maps, the existing area mapping will be preserved, and you can just tweak the link boundaries, or add or remove the link areas as necessary.
HTH