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