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