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