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)(15,24)(16,27)(17,28)(18,23)(19,21)(20,26)(22,25) involution — undirected(1,2,4,3)(5,7)(6,9)(8,11)(10,12)(13,15,18,26)(14,20,23,24)(16,17,19,25)(21,28,27,22)(6,10)(7,11)(13,16,18,19)(14,21,23,27)(15,25,26,17)(20,22,24,28)(6,10)(9,12)(13,17,19,26,18,25,16,15)(14,22,21,24,23,28,27,20)(1,3,4,2)(14,23)(20,24)(21,27)(22,28)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.