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