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