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