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