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