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