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