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