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