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