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