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