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