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