You could easily hide the grid or the pages by using the following attached properties:
1) BackgroundGrid.IsGridVisible - toggle grid visibility.
2) BackgroundPageGrid.IsGridVisible - toggle page visibility.
You could explore the other attached properties in these classes should you need more customization.
Note that these properties should be attached to a RadDiagram instance like follows:
Furthermore, we do provide quite extensive samples architecture where we try to highlight the most of our controls (in particular about 8 example for RadDiagram). In case you have missed our online demos, you could find them here
Hope this helps, please let us know if you need more info.
the Telerik team