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