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