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