Another -ic or -ical adjective question came up recently. This answer is sourced from http://forum.wordreference.com/showthread.php?t=11622 from the member Focalist:
1. relating to visual art, especially involving drawing, engraving, or lettering.
2 giving vividly explicit detail.
3 of or in the form of a graph.
1. of or in the form of a graph.
2 relating to visual art or computer graphics.
(Note that the adverbial form of both is: graphically)
Notice that, despite the overlaps, only the “giving vividly explicit detail” and “relating to computer graphics” are not common to both.