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