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