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