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)(11,19)(12,22)(13,17)(14,20)(15,16)(18,24)(21,23)(25,26,29,31)(27,35,37,40)(28,34,30,33)(32,36,39,38)(2,5)(6,7)(9,11)(10,15)(12,20)(13,16)(14,21)(17,19)(18,23)(22,24)(26,31)(27,36)(28,30)(32,35)(37,38)(39,40) involution — undirected(9,12,14,15,13,23,24,19)(10,16,18,22,17,11,20,21)(25,27,28,38,29,37,30,36)(26,32,33,35,31,39,34,40)(1,3,4,8)(2,6,5,7)(10,17)(11,16)(18,20)(21,22)(25,28,29,30)(26,33,31,34)(27,36,37,38)(32,40,39,35)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.