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