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