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)(17,18,21,23)(19,22,24,20)(25,26,30,32)(27,33,35,28)(29,37,38,31)(34,36,40,39)(1,2,5,3)(4,6,8,7)(9,11,13,12)(10,14,16,15)(17,18)(19,20)(21,23)(22,24)(29,38)(31,37)(34,40)(36,39)(4,8)(6,7)(17,19,21,24)(18,22,23,20)(25,27,30,35)(26,28,32,33)(29,34,38,40)(31,36,37,39)(1,3,5,2)(4,6,8,7)(9,10)(11,14)(12,15)(13,16)(17,18)(19,22)(20,24)(21,23)(25,28)(26,27)(29,36)(30,33)(31,34)(32,35)(37,40)(38,39)(1,4)(2,6)(3,7)(5,8)(9,12,13,11)(10,15,16,14)(17,20,21,22)(18,19,23,24)(25,29,30,38)(26,31,32,37)(27,34,35,40)(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.