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