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