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