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