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