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