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