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