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