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