Thanks for the interest in NodeXL.
There are several tools in NodeXL to help you group nodes and manage groups.
If your vertices have a group attribute you can use the NodeXL>Groups>By Vertex Attribute feature to collect nodes into their respective groups.
Groups can be displayed "in-a-box" by selecting the feature in the Document Action (aka "Graph Pane") Layout Menu - select Layout Options from the dropdown menu.
Groups can be displayed in an expanded or collapsed form. Select a group and set its display state using the right-click menu in the graph pane.
It is possible to filter groups of vertices as well using the Dynamic Filters option. After removing all nodes outside of a select group you could re-render the network with only that group displayed.
I hope that helps! Feel free to come back with any follow-on questions!