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