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