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