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