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