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