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