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