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