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