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