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