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