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