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