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)(11,17)(12,16)(13,18)(14,15)(19,24)(20,21)(22,23)(25,26)(27,29)(28,37)(30,38)(31,33)(32,36)(34,35)(39,40)(1,3,6,5)(2,7,4,8)(9,11)(10,13)(12,20)(14,18)(15,17)(16,24)(19,22)(21,23)(25,27,31,36)(26,32,33,29)(28,34,38,40)(30,35,37,39)(2,4)(3,5)(10,15)(11,18)(16,23)(19,20)(25,28,31,38)(26,30,33,37)(27,34,36,40)(29,39,32,35)(1,3,6,5)(2,7,4,8)(9,11)(10,13)(12,19)(14,18)(15,17)(16,21)(20,22)(23,24)(25,28)(26,30)(27,34)(29,39)(31,38)(32,35)(33,37)(36,40)(1,4,6,2)(3,7,5,8)(9,12,14,22)(10,16,15,23)(11,19,18,20)(13,21,17,24)(25,29,31,32)(26,27,33,36)(28,35,38,39)(30,40,37,34)(1,5,6,3)(2,7,4,8)(9,13)(10,11)(12,21)(14,17)(15,18)(16,19)(20,23)(22,24)(25,30)(26,28)(27,35)(29,40)(31,37)(32,34)(33,38)(36,39)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.