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