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