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