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