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