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