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