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)(27,34)(28,36)(29,33)(30,31)(32,35)(37,40)(38,39) involution — undirected(1,3)(2,5)(4,7)(6,8)(9,11)(10,14)(12,18)(13,19)(15,21)(16,17)(20,24)(22,23)(25,27,29,30)(26,31,33,34)(28,37,38,35)(32,39,40,36)(3,7)(5,8)(9,12,13,20)(10,15,16,22)(11,18,19,24)(14,21,17,23)(25,28)(26,32)(27,35)(29,38)(30,37)(31,36)(33,40)(34,39)(2,6)(3,7)(11,19)(14,17)(18,24)(21,23)(25,27,29,30)(26,31,33,34)(28,35,38,37)(32,36,40,39)(3,7)(5,8)(10,16)(14,17)(15,22)(21,23)(26,33)(31,34)(32,40)(36,39) 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.