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