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)(11,16)(12,15)(13,14)(18,20)(19,23)(25,26,29,30)(27,31,35,33)(28,36,37,32)(34,39,40,38)(3,8)(5,7)(9,11,14,12)(10,15,13,16)(26,30)(28,37)(31,33)(34,40)(11,12)(15,16)(17,18,21,20)(19,24,23,22)(25,27,29,35)(26,31,30,33)(28,34,37,40)(32,38,36,39)(1,3)(2,5)(4,8)(6,7)(9,12,14,11)(10,15,13,16)(17,19,21,23)(18,22,20,24)(25,26)(27,33)(28,32)(29,30)(31,35)(34,39)(36,37)(38,40)(1,2)(3,5)(4,6)(7,8)(9,13,14,10)(11,15,12,16)(17,20,21,18)(19,24,23,22)(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.