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