Click in the open space to add a node, drag from one node to another to add an edge.
Shift-drag a node to move the graph layout.
Click a node or an edge to select it.
Double-click a node to open the node editor.
Click on the Attributes View to open an editable list of node attributes.
Shift-Click an edge to edit edge value.
When a node is selected: R toggles reflexivity, Delete removes the node.
When an edge is selected: L(eft), R(ight), B(oth) change direction, Delete removes the edge.