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