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