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