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