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