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