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