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