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