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