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