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