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