To edit the graphical representation of data points choose the Edit | Point Symbols command or double-click the Points Symbols tree item.

The Symbol controls establishes the radius of a data point circle or other symbols (size in pixels) and can fully hide the points. The Image button allows display a image as point symbols.

The Symbol label box control the text label for a points.

The Circle Value group establishes the display of values as circles with minimal and maximum size corresponding to the minimum and maximum Z.