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