Files relate to each other in many different ways, and having only one Graph view causes a tangled web that is more confusing each time you create more and more nodes.
So I think its necessary, just like Juggl does, to have a save button and that way being able to open different configurations of graph view, each one with different colors, filtered tags and sizes
PS: yes, Juggl does it, but its system is not as fluid as the core Graph view.