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