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