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