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