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