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