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