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