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