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