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