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