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