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