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