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