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