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