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)(1,2)(3,4)(6,10)(11,12)(13,14)(15,19)(16,24)(17,21)(18,23)(20,25)(22,27)(26,28) involution — undirected(2,4)(13,15,19,14)(16,22,26,20)(17,21,18,23)(24,25,28,27)(2,4)(5,7,9,8)(6,11,10,12)(13,16)(14,20)(15,22)(17,25)(18,27)(19,26)(21,28)(23,24)(5,8,9,7)(6,11,10,12)(13,17,19,18)(14,21,15,23)(16,25,26,27)(20,28,22,24)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.