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