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