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