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