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