Using the Live Control tab, you can affect the Size of everything together (when in Master mode), or the size of individual cues (when in Cue mode). The picture below explains the various options.

Automatic Zoom out and Zoom up

You can automatically zoom the image out by pressing the button on the left.

You can automatically zoom the image up by pressing the button on the right.

Right click

Note that if you click the right mouse button on a Size slider, its value will be reset to 100%.