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