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