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