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