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