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)(11,18,21,15)(12,16,13,22)(19,24,20,23)(26,31)(27,28)(32,35)(36,38)(9,11,14,21)(10,15,17,18)(12,19,13,20)(16,23,22,24)(25,26,29,31)(27,33,28,37)(30,32,39,35)(34,38,40,36)(2,5)(6,8)(9,12,14,13)(10,16,17,22)(11,19,21,20)(15,23,18,24)(26,32)(30,39)(31,35)(33,34)(36,38)(37,40)(1,3,4,7)(2,6,5,8)(9,13,14,12)(10,16,17,22)(11,20,21,19)(15,23,18,24)(25,27)(26,33)(28,29)(30,36)(31,37)(32,34)(35,40)(38,39)(11,21)(15,18)(19,20)(23,24)(25,28,29,27)(26,34,31,40)(30,36,39,38)(32,33,35,37)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.