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