If you can't see the Plots: Scale Display options, click on the little right arrow to the left of "Plots: Scale Display" to make it point down; that will open the Plots: Scale Display panel.

You can control the way scales are displayed on your plots. Use the drop-down menus to select number format (Power or Long), whether or not to show tickmarks, scale numbers, and axis labels. (The axis labels are drawn from the X and Y axis controls.)

To control scales at the channel level--changing min, max, scale type, and argument--use the "Plot Scales" panel under the "Gating Hierarchy" panel and above the Illustration tab.