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