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