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)(12,15)(13,16)(17,21)(18,22)(19,23)(20,24)(25,26,31,40,30,34,29,33)(27,35,36,32,38,39,37,28)(2,5)(6,8)(9,11)(10,14)(12,19)(13,17)(15,23)(16,21)(18,20)(22,24)(25,27,30,38)(26,32,34,28)(29,36,31,37)(33,39,40,35)(11,17)(14,21)(18,19)(22,23)(25,27)(26,32)(28,34)(29,36)(30,38)(31,37)(33,39)(35,40) involution — undirected(9,12,13,20)(10,15,16,24)(11,18,17,19)(14,22,21,23)(25,28,30,32)(26,27,34,38)(29,39,31,35)(33,37,40,36)(1,3,4,7)(2,6,5,8)(10,16)(14,21)(15,24)(22,23)(25,29,30,31)(26,33,34,40)(27,36,38,37)(28,35,32,39)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.