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