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