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