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