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