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