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