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