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