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