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