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