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