Does anyone know of a tool, or any solution (preferably free), to automatically generate editable assembly dependency graphs (such as Visio diagrams)?

I have found similar threads online, but the several tools recommended (.Net Reflector Graph add-in, Dependency Visualizer, GraphViz, etc) generate only image files (PNG, JPG, SVG, etc).

The solution I need to reverse engineer is composed of over 75 projects, with hundreds of dlls. Even sub-system graphs are unintelligible, so we want to tweak / edit them, find common recurrences to isolate them into separate graphs, etc. We need something that can do the bulk brainless part for us, but that allows us to take over from there.

Btw, I did find tools to generate the respective matrix representation, which is great, but we still need to have a more straight-forward view of the depths of the graphs.

Thanks in advance.