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