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