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