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