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