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