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