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