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