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