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