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