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