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