The layout size can be changed with the mouse up-down with the left and right mouse buttons pressed.
An entire graph can be moved by selecting the graph in blank area with the mouse left button (no node of the graph shoud be chosen) and then by drag and drop operation.
A particular node can be moved by selecting it with the mouse left button and then by drag and drop operation.
A graph can be rotated in 3D either by pressing the mouse right button in blank area and then by drag and drop operation or by doing so while pressing the Ctrl key.
A node is selected by clicking the mouse left button on the node.
Selection of multiple nodes: Click the mouse left button on the node to select while pressing the Ctrl key in a viewport.
Selection of multiple nodes in a box region: Specify the box region by dragging the mouse left button while pressing the Shift key in a viewport.