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