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