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