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