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