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