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