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