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