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