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