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