One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,7,4,6)(9,10,12,16,13,17,20,15)(11,14,19,23,18,22,24,21)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,38)(37,40)(1,3,5,4)(2,6,8,7)(9,11)(10,14)(12,19)(13,18)(15,21)(16,23)(17,22)(20,24)(25,27)(26,30)(28,35)(29,34)(31,33)(32,38)(36,37)(39,40)(10,15)(12,20)(14,21)(16,17)(19,24)(22,23)(27,34)(29,37)(30,38)(32,40)(33,39)(35,36) involution — undirected(1,4,5,3)(2,7,8,6)(11,18)(14,22)(19,24)(21,23)(26,31)(30,33)(32,40)(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.