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