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