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