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