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