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