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