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