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