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