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