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