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