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