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