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