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