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