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