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