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