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