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