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