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