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