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