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)(25,26)(27,36)(28,38)(29,34)(30,33)(31,35)(32,37)(39,40)(9,11,13,19)(10,14,16,17)(12,18,21,24)(15,22,20,23)(25,27,30,37)(26,32,33,36)(28,39,34,31)(29,40,38,35)(1,3,5,4)(2,6,7,8)(25,28,31,27,30,34,39,37)(26,29,35,32,33,38,40,36)(9,12,13,21)(10,15,16,20)(11,18,19,24)(14,22,17,23)(26,33)(29,38)(32,36)(35,40)(1,4,5,3)(2,6,7,8)(11,19)(14,17)(18,24)(22,23)(25,29,31,32,30,38,39,36)(26,34,35,37,33,28,40,27)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.