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