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