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