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