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