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