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