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