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