Right click the graph and select Create>Property Node. On the diagram, find the property node, right click it and first select Change All to Write. Right click again and if you select Properties, you will see a list of all the available properties for the graph. The properties you want are XScale.Minimum, XScale.Maximum, XScale.Increment, YScale.Minimum, YScaleMaximum, and YScale.Increment. You can grow the single property node to have as many properties that you want. Once you have all the properties created, create front panel controls and wire them to the property node. See the attached picture.