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