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)(13,14,16,20,17,21,24,18)(15,19,22,27,23,26,28,25)(5,6)(7,10)(8,11)(9,12)(14,18)(15,22)(16,24)(20,21)(23,28)(25,27) involution — undirected(1,2,3,4)(5,7,10,6)(8,11,9,12)(15,23)(19,26)(22,28)(25,27)(5,8,10,9)(6,11,7,12)(13,15,16,22,17,23,24,28)(14,19,20,27,21,26,18,25)(5,9,10,8)(6,11,7,12)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.