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