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