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