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