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