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