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