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