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