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