to open GraphView in a sidepanel instead of "modal" you need to change the config of the position attribute (check documentation ):
position (v2 only) - Specifies where the graph panel opens up. Can be one of lhs (left), rhs (right), bhs (bottom), modal (modal window). Defaults to lhs.
and if it then opens in a Sidepanel in a fixed width, you can use my AdvancedPanelControl to resize or dettach or do anything with any sidepanel. (if you already have DocumentExplorer installed, i saw an eralier post of yours where you said you have it, it comes with the AdvancedPanelControl library already)
As an alternative there is another GraphView Plug made by @selcuk named GraphView Atas which i personally prefer over this one.
here are both side by side:
