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