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