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