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