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