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