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