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