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