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