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