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