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