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