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