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