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