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