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