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