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