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