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