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