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