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