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