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