In Visual Studio 2005 and prior you could export your code to Visio and view the relationships between the objects and what methods, properties and fields it had. This was great
With VS2005 & VS2008 you have the option of designing your own modelling language (DSL) here you can choose how your model is rendered, it would be a big investment if its just to make the diagrams look a little better, but it does provide you with option to customise how the code is generated from your model.