You can double click X axis to open Axis dialog. On Scale tab, set Rescale to Auto. Then choose Vertical on left panel of the dialog. Set Y axis' Rescale to Auto as well.
After this is done, if you change data in worksheet, the axis will auto update.
With Graph active, you can choose File: Save Template as to save it as your graph template. Then with other data selected, choose Plot: Template Library and find the template you saved to plot graphs with auto rescale in the future.
You can also choose File: Save Template to replace the system template. Then when you use Plot menu or graphing button to plot graph in the future, rescale will be auto.