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