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