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