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