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