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