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