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