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