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