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