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