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