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