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