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