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)(15,22)(16,19)(17,27)(18,23)(20,24)(21,25)(26,28) involution — undirected(1,2)(3,4)(14,19)(15,17)(16,25)(20,27)(21,22)(23,28)(24,26) involution — undirected(2,4)(6,9)(10,12) involution — undirected(5,7,8,11)(6,10,9,12)(13,15)(14,20)(17,18)(19,22)(21,23)(24,25)(27,28)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.