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