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