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