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