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