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