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