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