graph vs graphical

graph is a noun but graphical is not a noun.

Word	Noun	Adjective	Verb	Adverb
graph	Yes	No	Yes	No
graphical	No	Yes	No	No

graph (noun)	graphical (noun)
a visual representation of the relations between certain quantities, represented as points, plotted with reference to a set of axes
a visual display of information
a written symbol that is used to represent speech

graph (adjective)	graphical (adjective)
	relating to or presented by a graph
	written or drawn or engraved

graph (verb)	graphical (verb)
represent by means of a graph
plot upon a graph