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