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