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