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