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