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