Nearby the x or y-axis line, you can use the cursor to manually rescale or "stretch" the axis. Hover the cursor just outside of the axis (below the x-axis, for example). The cursor will turn into a "squiggly" arrow, which can be used to stretch the axis by dragging.
The axis is split into three regions. If you drag in the 1/3 near the end of the axis, the opposite end is fixed, and the near end is rescaled as you drag. If you drag in the middle 1/3 of the axis, the graph scale will translate.
Return the axis to the original scaling by choosing Undo from the Edit menu.