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