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