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