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