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