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