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