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