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