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