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