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