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