Absolutely, there are a few different ways to do this. In Game > Sharing an editor can add in the account names or emails of other editors. Also, students could share a login. This might make more sense if there was a single shared device they were using. In my own teaching, we do this, but I also have students specialize a bit so that not everyone is actually editing in ARIS. They might be creating art for the game or editing a script in Google Docs (or https://hackmd.io
if you want to write and preview html) that gets copied over ARIS at another time.
ARIS isn't really fancy like Google docs though, so you should be a bit careful with collaborative editing not to have editors overwrite each other's work. The separation of different functions into tabs in the editor can help with this, having one person creating conversations, another putting in art, etc.