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