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)(13,14,17,16)(15,21,24,28)(18,26,23,20)(19,27,22,25)(5,7)(6,9)(8,12)(10,11)(13,14)(15,22)(16,17)(18,20)(19,24)(21,27)(23,26)(25,28) involution — undirected(6,10)(9,11)(13,15,23,27,17,24,18,25)(14,19,26,28,16,22,20,21)(7,12)(9,11)(13,16,17,14)(15,22,24,19)(18,26,23,20)(21,25,28,27)(1,3,4,2)(6,10)(9,11)(14,16)(15,24)(20,26)(25,27)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.