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