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