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