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