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)(15,23)(16,21)(17,20)(18,22)(19,27)(24,28)(25,26) involution — undirected(6,9)(7,11)(13,15)(14,19)(16,28)(17,27)(18,24)(20,23)(21,26)(22,25) involution — undirected(1,2,3,4)(14,20)(15,24)(18,21)(19,28)(23,25)(26,27)(6,9)(10,12)(13,16,17,22)(14,21,20,18)(15,25,27,28)(19,24,23,26)(5,7,8,11)(6,10,9,12)(14,20)(15,26)(18,21)(19,25)(23,28)(24,27)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.