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