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