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