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