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