A quick search didn't turn up a RoboRIO fritzing part (it turned up a request for one with no replies about a year ago though). It is certainly possible to create a custom part however simple isn't how I would describe the process. A look at the users manual for the RoboRIO (assuming it is the one from National labs) indicates it shouldn't be all that bad to do if you are experienced at making Fritzing parts (however there is a quite steep learning curve to making parts). Here are links to a couple of tutorials which may give you an idea of what is involved in making a custom part (with the note that assistance is usually available here in the forums when the going gets tough 
):
I find Fritzing ideal for documenting one of interfaces and collections of processors and modules in breadboard view which I think is what you want to do.
Peter