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