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