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