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