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