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