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