One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,5)(3,7,8,6)(9,10)(11,16)(12,25)(13,29)(14,32)(15,19)(17,20)(18,27)(21,36)(22,34)(23,39)(24,40)(26,37)(28,31)(30,38)(33,35)(2,5)(6,7)(9,11)(10,16)(12,26)(13,30)(14,24)(15,22)(17,33)(18,21)(19,34)(20,35)(23,31)(25,37)(27,36)(28,39)(29,38)(32,40) involution — undirected(9,12,27,19,14,28,31,32,15,18,25,10,17,29,13,20)(11,21,37,34,24,38,30,40,22,26,36,16,33,39,23,35)(1,3,4,8)(2,6,5,7)(11,22)(16,34)(21,26)(23,30)(24,33)(35,40)(36,37)(38,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.