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