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