There is an adapter that goes from different sizes of standard vacuum tubes. I needed one to hook up my scroll saw to my shop vac. The adapter didn't really fit, so I had to take a knife to it to get it to fit under the table and onto the port. once I had the adapter fitted I left it on the saw all the time and hooked up the hose when I needed it.
You could do something similar to get an adapter to fit the end of the sander (duct tape comes to mind, but a more elegant method would work)