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