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