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