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