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